Communication apparatus and communication method as well as program

ABSTRACT

A communication apparatus, method and program that accommodate diverse usage are disclosed. In one example, a packet header is generated according to a CSI-2 standard. The packet header includes setting information of conditions set for data to be transmitted in a packet is placed. An extended header is also generated, into which the setting information is to be placed separately from the packet header. Then, into an unused region defined as a region that is not used in the existing CSI-2 standard with respect to a data type that is the setting information indicative of a type of the data to be transmitted in the packet, extension mode setting information indicative of whether or not an extension mode using the extended header is used is placed. The disclosed technology can be applied, for example, in a mobile device or in an in-vehicle camera.

TECHNICAL FIELD

The present disclosure relates to a communication. apparatus and acommunication method as well as a program, and particularly to acommunication apparatus and a communication. method as well as a programthat make it possible to deal with more diverse uses.

BACKGROUND ART

CSI (Camera Serial Interface)-2 ver4.0 whose standardization currentlyproceeds defines two packet structures including a packet structure inwhich the C-PHY is used for the physical layer and another packetstructure in which the D-PHY is used for the physical layer.

Further, since the CSI-2 standard has not only been used in mobiledevices but also been applied to various uses such as in-vehicle usesand IoT (Internet of Things) uses, it is supposed that, with theexisting packet structure, the CSI-2 fails to deal with such. uses.Therefore, the MIPI (Mobile Industry Processor Interface) alliance isinvestigating extension of the packet structure in terms of an existingpacket header and packet footer in order to make it possible to dealwith various uses.

Meanwhile, PTL 1 proposes a system that can use the CSI-2 standard todecrease the number of data buses when to connect a processing apparatusand a plurality of image sensors to each other.

CITATION LIST Patent Literature

-   [PTL 1]

Japanese Patent Laid-Open No. 2017-b 211864

SUMMARY Technical Problem

As described above, it is investigated to extend. the packet structureof a packet according to the CSI-2 standard, and in such extension ofthe packet structure, it is demanded to make it possible to transmit anincreased amount of information to deal with a variety of uses while thecompatibility of the existing CSI-2 standard is maintained.

The present disclosure has been. made n view of such a situation asdescribed above and makes it possible to deal with an increased varietyof uses.

Solution to Problem

A communication apparatus of a first aspect of the present disclosureincludes a packet header generation section configured to place settinginformation indicative of a condition set for data to be transmitted ina packet to generate a packet header in compliance with an existingCSI-2 standard, and an extended header generation section configured togenerate an extended header into which the setting information is to beplaced separately from the packet header. The packet header generationsection places, into an unused region defined as a region that is notused in the existing CSI-2 standard with respect to a data type thatincludes the setting information indicative of a type of the data to betransmitted in the packet, extension mode setting information indicativeof whether or not an extension mode using the extended header is used.

A communication. method or a program of the first aspect of the presentdisclosure includes placing setting information indicative of acondition set for data to be transmitted in a packet to generate apacket header in compliance with an existing CSI-2 standard, andgenerating an extended header into which the setting information is tobe placed separately from the packet header. Extension mode settinginformation. indicative of whether or not an extension mode using theextended header is used is placed into an unused region defined as aregion that is not used in the existing CSI-2 standard with respect to adata type that includes the setting information. indicative of a type ofthe data to be transmitted in the packet.

In the first aspect of the present disclosure, setting informationindicative of a condition set for data to be transmitted in a packet isplaced to generate a packet header in compliance with an existing CSI-2standard, and an extended header into which the setting information isto be placed is generated separately from. the packet header. Then,extension mode setting information indicative of whether or not anextension mode using the extended header is used is placed into anunused region defined as a region that is not used in the existing CSI-2standard with respect to a data type that includes the settinginformation indicative of a type of the data to be transmitted in thepacket.

A communication apparatus of a second aspect of the present disclosureincludes a packet header detection section configured to detect a packetheader in which setting information indicative of a condition set fordata to be transmitted in a packet is placed, according to an existingCSI-2 standard, and an interpretation section configured to interpretthe setting information placed in an extended header separate from thepacket header. The packet header detection section causes switching tobe performed between reception of a packet having a packet structure incompliance with the existing CSI-2 standard and reception of a packethaving a packet structure in an extension mode, according to extensionmode setting information that is placed into an unused region defined asa region not used in the existing CSI-2 standard with respect to a datatype including the setting information indicative of a type of the datato be transmitted in the packet and that indicates whether or riot theextension mode using the extended header is used.

A communication method or a program of the second aspect of the presentdisclosure includes detecting a packet header in which settinginformation indicative of a condition. set. for data to be transmittedin a packet is placed, according to an existing CSI-2 standard, andinterpreting the setting information placed in an extended headerseparate from the packet header. Switching is performed betweenreception of a packet having a packet structure in compliance with theexisting CSI-2 standard and reception of a packet having a packetstructure in an extension mode, according to extension mode settinginformation that is placed into an unused region defined as a region notused in the existing CSI-2 standard with respect to a data typeincluding the setting information indicative of a type of the data to betransmitted in the packet and that indicates whether or not theextension. mode using the extended. header is used.

In the second aspect of the present disclosure, a packet header in whichsetting information indicative of a condition set for data to betransmitted in a packet is placed, is detected according to an existingCSI-2 standard, and the setting information placed in an extended headerseparate from the packet header is interpreted. Then, switching isperformed between reception of a packet having a packet structure incompliance with the existing CSI-2 standard and reception of a packethaving a packet structure in an extension mode, according to extensionmode setting information that is placed into an unused region defined asa region not used in the existing CSI-2 standard with respect to a datatype including the setting information indicative of a type of the datato he transmitted in the packet and that indicates whether or not theextension mode using the extended header is used.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a block diagram depicting an example of a configuration of afirst embodiment of a communication system to which the presenttechnology is applied.

FIG. 2 is a block diagram depicting an example of a configuration of asecond embodiment of a communication system to which. the presenttechnology is applied.

FIG. 3 is a view depicting a first structure example of an entire packetstructure of an extended packet for the D-PHY.

FIG. 4 is a view depicting a first structure example of a packetstructure of an extended short packet for the D-PHY.

FIG. 5 is a view depicting a first structure example of a packetstructure of an extended long packet for the D-PHY.

FIG. 6 is a view depicting a first structure example of an entire packetstructure of an extended packet for the C-PHY.

FIG. 7 is a view depicting a first structure example of a packetstructure of an extended short packet for the C-PHY.

FIG. 8 is a view depicting a first structure example of a packetstructure of an extended long packet for the C-PHY.

FIG. 9 is a block diagram depicting an example of a configuration of animage sensor.

FIG. 10 is a block diagram depicting an example of a configuration of anapplication processor.

FIG. 11 is a flow chart illustrating a process in which the image sensortransmits a packet.

FIG. 12 is a flow chart illustrating an extension mode transmissionprocess.

FIG. 13 is a flow chart illustrating a process fa which the applicationprocessor receives a packet.

FIG. 14 is a flow chart illustrating an extension mode receptionprocess.

FIG. 15 is a view depicting a second structure example of an entirepacket structure of an extended packet for the D-PHY.

FIG. 16 is a view depicting a second structure example of a packetstructure of an extended long packet for the D-PHY.

FIG. 17 is a view depicting a second structure example of a packetstructure of an extended short packet for the C-PHY.

FIG. 18 is a view depicting a second structure example of a packetstructure of an extended long packet for the C-PHY.

FIG. 19 depicts block diagrams of a modification of a configuration forswitching the D-PHY and the C-PHY.

FIG. 20 is a block diagram depicting an example of a configuration of anembodiment of a computer to which the present technology is applied.

DESCRIPTION OF EMBODIMENTS

In the following, particular embodiments to which the present technologyis applied are described in detail with reference to the drawings.

<Example of Configuration of Communication System>

FIG. 1 is a block diagram depicting an example of a configuration of afirst embodiment of a communication system to which. the presenttechnology is applied.

As depicted in FIG. 1, the communication system ll is configured from animage sensor 21 and an application processor 22 connected to each otherby a bus 23. For example, the communication system 11 is used. for CSI-2connection in the inside of an existing mobile device such as what iscalled a smartphone.

The image sensor 21 is configured such that an extension mode compatibleCSI-2 transmission circuit 31 is incorporated together with, forexample, a lens and an imaging device (either of them is not depicted).For example, the image sensor 21 transmits image data regarding an imageacquired by imaging by the imaging device to the application processor22 by the extension mode compatible CSI-2 transmission circuit 31.

The application processor 22 is configured such that an extension modecompatible CSI-2 reception circuit 32 is incorporated together with anLSI (Large Scale Integration) that performs processes according tovarious applications to be executed by the mobile device that includesthe communication system 11. For example, the application processor 22receives image data transmitted from the image sensor 21, by using theextension mode compatible CSI-2 reception circuit 32, and can perform aprocess according to the application for the image data by using theLSI.

The bus 23 is a communication path for transmitting a signal incompliance with the CSI-2 standard, and the transmission distance overwhich the bus 23 can transmit a signal is approximately 30 cm, forexample. Further, the bus 23 connects the image sensor 21 and theapplication processor 22 to each other by a plurality of signal lines(I2C, CLKP/N, DOP/N, D1P/N, D2P/N, and D3P/N) as depicted in FIG. 1.

The extension mode compatible CSI-2 transmission circuit 31 and theextension mode compatible CSI-2 reception circuit 32 are ready forcommunication by an extension mode extended from the CSI-2 standard andcan perform transmission and reception. of a signal between them. It isto be noted that detailed configurations of the extension modecompatible CSI-2 transmission circuit 31 and the extension modecompatible CSI-2 reception circuit 32 are described later with referenceto FIGS. 9 and 10.

FIG. 2 is a block diagram depicting an example of a configuration of asecond embodiment of the communication system to which the presenttechnology is applied.

As depicted in FIG. 2, a communication system IIA is configured such.that the image sensor 21 and a serializer 25 are connected to each otherby a bus 24-1 while the application processor 22 and a deserializer 26are connected to each other by a bus 24-2 and such that the serializer25 and the deserializer 26 are connected to each other by a bus 27. Forexample, the communication system 11A is used for connection in anexisting in-vehicle camera.

Here, the image sensor 21 and the application processor 22 areconfigured similarly to the image sensor 21 and the applicationprocessor 22 of FIG. 1, respectively, and detailed description of themis omitted.

The buses 24-1 and 24-2 are communication paths for transmitting asignal in compliance with the CSI-2 standard, similarly to the bus 23 ofFIG. 1, and include a plurality of signal lines (HS-GPIC., I2C, CLKP/N,DOP/N, DiP/N, D2P/N, and D3P/N) as depicted in FIG. 2.

The serializer 25 includes a CSI-2 reception circuit 33 and a SerDes(Serializer Deserializer) transmission circuit 34. For example, theserializer 25 acquires a bit-parallel signal transmitted thereto fromthe image sensor 21, by communication in compliance with the CSI-2standard performed by the CSI-2 reception circuit 33 with the extension.mode compatible CSI-2 transmission circuit 31. Then, the serializer 25converts the acquired signal into a bit-serial signal, and the SerDestransmission circuit 34 performs communication with the SerDes receptioncircuit 35 by one lane to transmit the signal to the deserializer 26.

The deserializer 26 includes a SerDes reception circuit 35 and a CSI-2transmission circuit 36. For example, the deserializer 26 acquires abit-serial signal transmitted. by communication of the SerDes receptioncircuit 35 performed with the SerDes transmission. circuit. 34 by onelane. Then, the deserializer 26 converts the acquired signal into abit-parallel signal, and the CSI-2 transmission circuit 36 performscommunication in compliance with the ordinary CSI-2 standard with theextension mode compatible CSI-2 reception circuit 32 to transmit thebit-parallel signal to the application processor 22.

The bus 27 is a communication. path for transmitting a signal incompliance with a SerDes standard other than the CSI-2 , such as FPD(Flat Panel Display)-LINK III, and the transmission distance over whicha signal can be transmitted is approximately 15 m.

The communication systems 11 and 11A configured in such a manner can.transmit and receive data with a packet having a packet structureextended in such a manner as described later, by the extension modecompatible CSI-2 transmission circuit 31 and the extension modecompatible CSI-2 reception circuit 32. Consequently, they can becompatible with an increased variety of uses such as RAW24, SmartROI(Region of Interest), or GLD (Graceful Link Designation) as describedlater.

<First Structure Example of Packet Structure>

A first structure example of the packet structure of a packet that isused in communication between the extension mode compatible CSI-2transmission circuit 31 and the extension mode compatible CSI-2reception circuit 32 is described with reference to FIGS. 3 to 8.

FIG. 3 depicts an entire packet structure of a packet used. in anextension mode of CSI--2 in the case where the physical layer is theD-PHY (the packet is hereafter referred to as an extended packet for theD-PHY).

As depicted in FIG. 3, the extended packet for the D-PHY has a packetstructure in which the packet header and the packet footer are same asthose in the existing CSI-2 standard. For example, in the packet header,a VC (VirtualChannel) indicative of the number of lines for a virtualchannel, a data type (DataType) indicative of a type of data, a 4C (WordCount) indicative of a data length of the payload, and VCX/ECC areplaced. On the other hand, in the packet footer, a CRC (CyclicRedundancy Check) is placed.

Here, in the existing CSI-2 standard, the data type to be transmitted bythe packet header is defined as “reserve” at 0x38 to 0x3F. Therefore, inthe extended packet for the D-PHY, setting information for identifyingthe extension mode on the reception side is newly defined by using thedata type defined as “reserve” in the existing CSI-2 standard.

For example, as the data type,

in the case of DataType[5:3]=3′b111, the extension. mode

DataType[2]=Reserve (RES: reservation for extension in the future)

DataType[1:0]=extension mode type (four extension modes are prepared)are defined.

In particular, among 0x38 to 0x3F for the data type defined as “reserve”in the existing CSI-2 standard, for example, DataType [5:3] is definedas extension mode setting information, and DataType[1:0] is defined asextension type setting information. The extension mode settinginformation indicates whether or not the extension mode is applied, and,for example, in the case where DataType[5:3] is 3′b111, it is indicatedthat the extension mode is applied. Further, in the case where fourtypes, that is, an extension mode 0, an extension mode 1, an extensionmode 2, and an extension. mode 3, are prepared as the type of theextension mode, the extension type setting information indicates whichof these types the extension mode is. For example, in the case whereDataType[1:0] is 2′b00, this indicates that the type of the extensionmode is the extension mode 0.

Further, in the extension mode 0 (DataType[1:0]=2′b00), for example, apacket structure in which the payload is split into four is defined. inparticular, the payload in the extension mode 0 is split into anextended payload header (ePH: extended Payload Header), an optionalextended payload. header (OePH: Optional extended Payload Header), alegacy payload (Legacy Payload), and an optional extended payload footer(OePF: Optional extended Payload Footer) as depicted in FIG. 3.

The extended payload header is placed at the top corresponding to thepayload of the existing CSI-2 standard, and in the extension mode, it isnecessary to transmit the extended payload header without fail. Forexample, the extended payload header is configured from settinginformation including an identification flag of the SROI, an extended VC(VirtualChannel), extended. DataType, a selection flag of the OePH, aselection flag of the OePF, or the like as depicted in FIG. 3. Here, bythe extended VC, the VC that is configured from 4 bits in the existingCSI-2 standard is extended to 8 bits, and by the extended. DataType, theDataType that is configured from 4 bits in the existing CSI-2 standardis extended to 8 bits.

For example, in a packet for the D-PHY, the VC of the existing packetheader already exists in 4 bits, and. bye defining the extended VC ofthe extended payload header with 4 bits, totaling 8 bits are used. Inparticular, OePH[7:0]={5′h00, RSID, XY_POS, MC} and OePF[3:0]={3′h0,pCRC} can be defined, and ON/OFF of packet transmission necessary foreach use can. be controlled.

The optional extended payload header and the optional extended payloadfooter are selectively transmitted according to a use.

The legacy payload corresponds to a payload same as that of the existingCSI-2 standard.

By setting the extended payload header, optional extended payloadheader, and optional extended payload footer as necessary in such amanner, data suitable for various uses can be transmitted. Further, datato be transmitted by the extended payload header, optional extendedpayload header, and optional extended payload footer is assumed to be anECC (Error Correction. Code) of 26 bits+6 bits. By this, it is possibleto divert a circuit for an existing payload header to suppress increaseof the circuit scale and achieve improvement of the error tolerance.

As a particular example of application of such an extended packet forthe D-PHY as described above, a packet structure of a short packet usedin the extension mode of CSI-2 in the case where the physical layer isthe D-PHY (such short packet is hereinafter referred to as an extendedshort packet for the D-PHY) is depicted in FIG. 4. Similarly, in FIG. 5,there is depicted a packet structure of a long packet used in theextension mode of CSI-2 in the case where the physical layer is theD-PHY (such long packet is hereinafter referred to as an extended longpacket for the D-PHY).

In such an extended short packet for the D-PHY as depicted in FIG. 4,the extension type setting information of the data type placed in thepacket header indicates that the type of the extension mode is theextension mode 0 (DT[5:0]=0x1C (5′b111_0_0)). Further, the short packetsetting information of the data type placed in the extended payloadheader indicates that the packet is a short packet (DT[7:0]=0x00 (FrameStart Code (Short Packet))).

In the case where the extension. mode is used. and. the data type placedin the extended payload header is DT[7:0]=0x00 to 0x0F in such a manner,the packet is the extended short packet, and data including the ShortPacket Data Field for the extended short packet is transmitted to theoptional extended payload. header without fail. This Short Packet DataField is same as that defined in the existing CSI -2 standard.

It is to be noted that, upon transmission of an extended short packet,although the MC (MessageCount for GLD) and the RSID (in-vehicle linenumber and SourcelD) included in the optional extended. payload headermay be transmitted, since the legacy payload and the pCRC areunnecessary, their transmission is inhibited. If they are transmitted inerror, then they are ignored on the reception side.

An extended short packet having such a packet structure as depicted inFIG. 4 can be extended in regard to the data bit width of the data typeand the virtual channel in comparison with an extended short packet in.compliance with the existing CSI-2 standard and can deal with varioususes defined by the optional extended payload header. Further, in thecase where such functions are unnecessary, an extended short packet incompliance with the existing CSI-2 standard may be transmitted togetherwith an extended long packet.

In such an extended long packet for the D-PHY as depicted in FIG. 5, theextension type setting information for a data type placed in the packetheader indicates that the type of the extension mode is the extensionmode 0 (DT[5:0]=0x1C (5′b111_0_0)). Further, the short packet settinginformation for a data type placed in the extended payload headerindicates that the packet is not the short packet but other packets (DT[7:0] is not 0x00 to 0x0F but the other (=extended Long Packet)).Accordingly, by the extended long packet, data including the ShortPacket Data Field is not transmitted.

Further, according to the setting of the extended payload header, theoptional extended payload header, legacy payload, and optional extendedpayload footer are placed in and transmitted together with the payloadin the existing CSI-2 standard. Since they are placed in and transmittedtogether with the existing payload in such a manner, they are recognizedby the existing SerDes transmission circuit 34 and SerDes receptioncircuit 35 (FIG. 2), similarly to image data transmitted by the existingpayload, and are transmitted as they are to a succeeding stage.

Then, the application processor 22 in the last stage can decide that theextension mode is used, on the basis of the data type DT [5:0] of thepacket header. Accordingly, the application processor 22 can interpretthe content of the payload in order from the extended payload header toextract data of the desired. extension. mode.

FIG. 6 depicts an entire packet structure of a packet used is theextension mode of CSI-2 in the case where the physical layer is theC-PHY (the packet is hereafter referred to as an extended packet for theC-PHY). It is to be noted that description of a configuration of theextended packet for the C-PHY depicted in FIG. 6 which is common to theextended packet for the D-PHY depicted. in FIG. 3 is omitted, and only adifferent configuration is described.

For example, is the extended packet for the C-PHY, the extension mode isidentified from the data type, and all data according to eachapplication to be executed by the application processor 22 is embeddedin and transmitted. together with the payload, similarly to the extendedpacket for the D-PHY of FIG. 3.

As depicted in FIG. 6, in the case of the extended packet for the C-PHY,the packet header is transmitted twice similarly to the case of thepacket for the C-PHY in compliance with the existing CSI-2 standard, andbecause the C-PHY converts 16 bits into seven symbols, data is arrangedin a unit of 16 bits. Further, the extended payload header is placed atthe top of the payload. However, as for a virtual channel, in the caseof the C-PHY, since the top of the existing packet header is defined asReserve due to this, the virtual channel is not placed in the extendedpayload header. Needless to say, a virtual channel may be placed in theextended payload header, similarly to the extended packet for the D-PHY.

Further, since the number of bits of the optional extended payloadheader and the optional extended payload footer is great, a flag OePHFis prepared, and in the case where this flag is 1, OePH/OePF informationis transmitted next. Then, after the ePH information and OePHinformation, a CRC is transmitted as the extended payload header, and apacket header configured similarly is transmitted repeatedly twice. Byusing a mechanism and a structure same as the existing mechanism andstructure by which a packet header is transmitted twice, both circuitreusability and error tolerance can be achieved

As a particular example of application of such an extended packet forthe C-PHY as described above, FIG. 7 depicts a packet structure of ashort packet to be used in the extension mode of CSI-2 in the, casewhere the physical layer is the C-PHY (such short packet is hereinafterreferred to as an extended short packet for the C-PHY). Similarly, FIG.8 depicts a packet structure of a long packet to be used in theextension mode of CSI-2 in the case where the physical layer is theC-PHY (such long packet is hereinafter referred to as an extended longpacket for the C-PHY).

It is to be noted that the extended short packet for the C-PHY depictedin FIG. 7 is not much different in packet structure from the extendedshort packet for D-PHY depicted in FIG. 4 and that the extended longpacket for the C-PHY depicted in FIG. 8 is not much different in packetstructure from the extended long packet for D-PHY depicted in FIG. 5.

<Example of Configuration of Image Sensor and Application. Processor>

FIG. 9 is a block diagram depicting an example or a configuration of theimage sensor 21 that includes the extension mode compatible CSI-2transmission circuit 31.

As depicted in FIG. 9, the image sensor 21 includes, in addition to theextension mode compatible CSI-2 transmission circuit 31, a pixel 41, anAD converter 42, an image processing section 43, a pixel CRC calculationsection 44, a physical layer processing section 45, an I2C/I3C slave 46,and a register 47. Further, the extension mode compatible CSI-2transmission circuit 31 includes a packing section 51, a packet headergeneration section 52, a payload header generation section 53, a payloadfooter generation section 54, selection sections 55 and 56, a CRCcalculation section 57, a lane distribution section 58, a CCI slave 59,and a controller 60.

The pixel 41 outputs an analog pixel signal according to a light amountof received light, and the AD converter (ADC: Analog-to-DigitalConverter) 42 digitally converts the pixel signal outputted from thepixel 41 and supplies the digital pixel signal to the image processingsection 43. The image processing section (ISP: Image Signal Processor)43 supplies image data obtained by carrying out various image processesfor the image based on the pixel signal, to the pixel CRC calculationsection 44 and the packing section 51. Further, the image processingsection 43 supplies a data. enable signal data en indicative of whetheror not image data is valid, to the packing section 51 and the controller60.

The pixel CRC calculation section 44 calculates the CRC for each pixelin image data supplied from the image processing section 43 and suppliesthe CRC to the payload footer generation section 54.

The physical layer processing section 45 can execute a physical layerprocess for both the C-PHY and the D-PHY. For example, the physicallayer processing section 45 executes a physical layer process for theC-PHY in the case where a C layer enable signal cphy_en supplied fromthe controller 60 is valid, while the physical layer processing section45 executes a physical layer process for the D-PHY in the case where theC layer enable signal cphy_en is invalid. Then, the physical layerprocessing section 45 supplies packets divided into four lanes by thelane distribution section 58, to the application processor 22.

The I2C/I3C slave 46 performs communication according to the initiativeof an I2C/I3C master 72 (FIG. 10) of the application processor 22, onthe basis of the standard of I2C (Inter-Integrated Circuit) or I3C(Improved Inter Integrated Circuits).

Into the register 47, various settings transmitted. from the applicationprocessor 22 are written. through the I2C/I3C slave 46 and the CCI slave59. Here, as the settings to be written into the register 47, forexample, settings according to the CSI-2 standard, extension modesettings indicative of whether or not the extension mode is used, fixedcommunication settings necessary for communication in the extensionmode, and so forth are available.

The packing section 51 performs a packing process of placing image datasupplied from the image processing section 43 into the payload of apacket and supplies the payload to the selection section 55 and the lanedistribution section 58.

If an instruction for Generation of a packet header is receivedaccording to a packet header generation. instruction signal ph_gosupplied from the controller 60, the packet header generation section 52generates a packet header and supplies the packet header to theselection section 55 and the lane distribution section 58.

In particular, according to the existing CSI-2 standard, the packetheader generation section 52 generates a packet header in which settinginformation indicative of conditions set for data to be transmitted by apacket, such as a data type indicative of a type of the data, is placed.Further, the packet header generation section 52 places extension modesetting information indicative of whether or not the current mode is theextension mode that uses an extended header, into the unused regiondefined as a region that is not used in the existing CSI-2 standard withrespect to the data type that is setting information indicative of atype of data to be transmitted by the packet. Further, the packet headergeneration section 52 places extension type setting informationindicating which of a plurality of types of the extension mode preparedas the extension mode is used for the extension mode, into the unusedregion.

The payload header generation section 53 generates an extended payloadheader and an optional extended payload header according to an extendedpayload header generation instruction signal epf_go and an extendedpayload header enable signal ePH_en supplied from the controller 60,respectively, and supplies them to the selection section 56 and the lanedistribution section 56. Further, to the payload header generationsection 53, an in-vehicle line number, a source ID (identification), andso forth are supplied according to a use of the image sensor 21, andthey are placed into the extended payload header or the optionalextended payload header, as needed.

In other words, the payload header generation section 53 generates anextended payload header into which, for example, such settinginformation as depicted in FIG. 3 is to be placed separately from apacket header generated by the packet header generation section 52.Further, in the case where the optional extended header is to betransmitted, the payload header generation section 53 places optionalextended header setting information indicating that an optional extendedheader is to be transmitted, into the extended header as the optionalextended header setting information (0ePH[7:0]) indicative of whether ornot an optional extended header is to be transmitted, and generates anoptional extended header following the extended header.

The payload footer Generation section 54 generates an optional extendedpayload footer according to an extended payload footer generationinstruction signal epf_go and an extended payload header enable signalePF-en supplied from the controller 60 and supplies the optionalextended payload footer to the selection section 56 and the lanedistribution section 58.

In particular in the case where the packet to be transmitted is theextension mode is an extended long packet in which data to betransmitted as the payload is placed in the existing CSI-2 standard, thepayload footer generation section 54 generates an optional extendedfooter that is to be placed following the legacy payload into which datais to be placed.

Further, to the packet header generation section 52, payload headergeneration section 53, and payload footer generation section 54, a Clayer enable signal cphy_en is supplied from the controller 60. Then, inthe case where the C layer enable signal cphy_en indicates valid, thepacket header generation section 52 generates a packet header for theC-PHY, and the payload header generation section 53 generates anextended payload header and an optional extended payload header for theC-PHY while the payload footer generation section 54 generates anoptional extended payload footer for the C-PHY. On the other hand, isthe case where the C layer enable signal cphy_en indicates invalid, thepacket header generation section 52 generates a packet header for theD-PHY, and the payload. header generation section 53 generates anextended payload header and an optional extended payload header for theD-PHY while the payload footer generation section 54 generates anoptional extended payload footer for the D-PHY.

In the case where the C layer enable signal cphy_en is valid, theselection section 55 selects, according to the C layer enable signalcphy_en supplied from the controller 60, a packet header supplied fromthe packet header generation section 52 and supplies the packet headerto the selection section 56. On the other hand, in the case where the Clayer enable signal cphy_en is invalid, the selection section 55 selectsa payload supplied from the packing section 51 and supplies the payloadto the selection section 56.

According to a data selection signal data_sel supplied from thecontroller 60, the selection section 56 selects and supplies, to the CRCcalculation section 57, any of a packet header or a payload selectivelysupplied through the selection section 55, an extended payload headerand an optional extended. payload header supplied from the payloadheader generation section 53, or an optional extended payload footersupplied from the payload footer generation section 54.

The CRC calculation section 57 obtains, by arithmetic operation, a CRCof a packet header, a payload, an extended payload header, an optionalextended payload header, or an optional extended payload footerselectively supplied thereto through the selection section 56 andsupplies the CRC to the lane distribution section 58.

Under the control of the controller 60, the lane distribution section 58distributes a payload supplied from the packing section 51, a packetheader supplied from the packet header generation. section 52, anextended payload header and an optional extended payload header suppliedfrom the payload header generation section 53, an optional extendedpayload footer supplied from the payload footer generation section 54,and a CRC suppled from the CRC calculation section 57, into four lanesin compliance with the CSI-2 standard, and supplies them in the fourlanes to the physical layer processing section 45.

The CCI (Camera. Control Interface) slave 59 performs communicationaccording to the initiative of a CCI master 88 (FIG. 10) of theapplication processor 22, on the basis of the CSI-2 standard.

The controller 60 reads out various settings stored in the register 47and performs control of the blocks configuring the extension. modecompatible CSI-2 transmission circuit 31, according to the settings. Forexample, the controller 60 controls switching between transmission of apacket having a packet structure in. compliance with the existing CSI-2standard and transmission of a packet having a packet structure in theextension mode, according to the content of data of a transmissiontarget.

The image sensor 21 is configured in such a manner as described aboveand can generate an extended packet having such a packet structure asdescribed hereinabove with reference to FIGS. 3 to 8, therebytransmitting the extended packet to the application processor 22.

FIG. 10 is a block diagram depicting an example of a configuration ofthe application processor 22 that includes the extension mode compatibleCSI-2 reception. circuit 32.

As depicted in FIG. 10, the application processor 22 includes a physicallayer processing section 71, the I2C/I3C master 72, a register 73, and acontroller 74, in addition to the extension mode compatible CSI-2reception circuit 32. Further, the extension mode compatible CSI-2reception circuit 32 includes a packet header detection section 81, alane merging section 82, an interpretation section 83, selectionsections 84 and 85, a CRC calculation section 86, an unpacking section87, and the CCI master 88.

The physical layer processing section 71 can execute a physical layerprocess for both the C-PHY and the C-PHY. As described above, thephysical layer processing section 45 of the image sensor 21 performs aphysical layer process for either the C-PHY or the D-PHY, and thephysical layer processing section 71 executes a physical layer processsame as that executed by the physical layer processing section 45.

The I2C/I3C master 72 performs communication with the I2C/I3C slave 46(FIG. 9) of the image sensor 21 according to the initiative thereof, onthe basis of the I2C or I3C standard.

Into the register 73, various settings to be written into the register47 of the image sensor 21 are recorded by the controller 74.

The controller 74 performs control of the respective blocks configuringthe application processor 22.

The packet header detection section 81 detects a packet header from apacket supplied from the physical layer processing section 71 and checksa data type placed in the packet header. Regarding the data type of thepacket header, in the case where the extension mode setting informationindicates the extension mode (DataType[5:3]=3′b111), the packet headerdetection section 81 then supplies an extension mode detection flagindicative of the extension mode to the interpretation section 83,selection section 84, and selection section 85. Further, the packetheader detection section 81 supplies a merge enable signal mrg_enindicative of whether or not merge of the divided four lanes is to bemade valid, to the lane merging section 82 on the basis of the packetheader.

In particular, the packet header detection section 81 detects a packetheader in which setting information (data type and so forth) indicativeof conditions set for data to be transmitted by a packet is placed,according to the existing C8I-2 standard. At this time, the packetheader detection section 81 outputs an extension mode detection flagaccording to extension mode setting information that indicates whetheror riot the extension mode using an extended header is used and that isplaced in the unused region defined as a region not used in the existingCSI-2 standard with respect to the data type that is setting informationindicative of a type of data to be transmitted by a packet. Thus,switching between reception of a packet having a packet structure incompliance with the existing CSI-2 standard and reception of a packethaving a packet structure in the extension mode is performed. Further,according to the extension mode type information placed in the unusedregion of the data type defined as a region that is not used in theexisting CSI-2 standard, the packet header detection section 81recognizes which of a plurality of types of the extension mode preparedas the extension mode is used for the extension mode.

In the case where the merge enable signal mrg_en supplied from thepacket header detection section 81 is valid, the lane merging section 82merges the packets divided into the four lanes and supplied from thephysical layer processing section 71. Then, the lane merging section 82supplies the packet of one lane to the interpretation section 83,selection section 84, and selection section 85.

In the case where the extension mode detection flag supplied from thepacket header detection section 81 indicates the extension mode, theinterpretation section 83 reads out the extended payload header,optional extended payload header, and optional extended payload footerfrom the packet supplied from the lane merging section 82, on the basisof the packet structure of the extension mode. Then, the interpretationsection 83 interprets setting information placed in the extended payloadheader, optional extended payload header, and optional extended payloadfooter.

In particular, the interpretation section 83 receives the extendedpayload header placed at the top of the payload in compliance with theexisting CSI-2 standard, as the extended header, and interprets settinginformation placed in the extended payload header. Further, in the casewhere the optional extended header setting information placed in theextended header indicates transmission of an optional extended headerthat is to be transmitted selectively according to a use, theinterpretation section 83 receives the optional extended. headerfollowing the extended header and interprets setting information placedin the optional extended header. Further, in the case where the packetto be transmitted in the extension mode is an extended long packet inwhich data to be transmitted as the payload in the existing CSI-2standard is placed, the interpretation section 83 receives the optionalextended. footer placed following the legacy payload in which data isplaced, and interprets the optional extended footer.

Then, the interpretation section 83 reads out, for example, anin-vehicle line number, a source ID, and so forth placed in the optionalextended payload header and outputs them to an LSI (not depicted) in thefollowing stage.

It is to be noted that, in the case where the extension mode detectionflag supplied form the packet header detection section 81 does notindicate the extension mode, that is, in the case where a packet havingan existing packet structure is supplied, the interpretation section 83stops without performing such processes as described above.

The selection section 84 selectively supplies data to the unpackingsection 87 on the basis of the packet structure of an existing packet orthe packet structure of the extended packet, according to an extensionmode detection flag supplied form the packet header detection section81.

The selection section 85 selectively supplies data to the CRCcalculation section 86 on the basis of the packet structure of anexisting packet or the packet structure of the extended packet,according to an extension mode detection flag supplied form the packetheader detection section 81.

The CRC calculation section 86 arithmetically operates a CRC of a packetheader, payload, extended payload header, optional extended payloadheader, or optional extended payload footer selectively supplied throughthe selection section 85. Then, in the case where a CRC error isdetected, the CRC calculation section $6 outputs a crc error detection.signal indicative of this to the LSI (not depicted) in the followingstage.

The unpacking section 87 performs an unpacking process of extractingimage data placed in the payload selectively supplied through theselection section 84 and outputs acquired image data to the LSI (notdepicted) in the following stage.

The CCI master 88 performs communication with the CCI slave 59 (FIG. 9)of the image sensor 21 according to the initiative thereof, on the basisof the CSI-2 standard.

The application processor 22 is configured in such a manner as describedabove. The application processor 22 can receive an extended packettransmitted from the image sensor 21 and interpret setting informationplaced in the extended payload header, optional extended payload header,and optional extended payload footer to acquire image data.

<Communication Process>

A communication process performed by the image sensor 21 and theapplication processor 22 is described with reference to FIGS. 11 to 14.

FIG. 11 is a flow chart illustrating a process in which the image sensor21 transmits a packet.

For example, if the image sensor 21 is connected to the applicationprocessor 22 through the bus 23, then processing is started. In stepS11, the controller 60 decides whether or not an extension mode is to beused when to start communication with the application processor 22. Forexample, the controller 60 confirms the extension mode setting stored isthe register 47 and decides, is the case where an extension mode settingindicating that the extension mode is to be used is written by theapplication processor 22, that the extension mode is to be used.

In the case where the controller 60 decides in step S11 that theextension mode is not to be used, the processing advances to step S12.

In step S12, the I2C/I3C slave 46 receives a transmission startingcommand of image data transmitted from the application processor 22 (instep S54 of FIG. 13 described later). Further, the I2C/I3C slave 46receives a communication setting in compliance with the CSI-2 standardtransmitted together with the transmission starting command and writesthe communication setting into the register 47 through. the CCI slave59.

In step S13, the image sensor 21 executes a conventional packettransmission process of transmitting a packet having a packet structurein compliance with the existing CSI-2 standard to the applicationprocessor 22, on the basis of the communication setting stored in theregister 47.

On the other hand, in the case where the controller 60 decides in step311 that the extension mode is to be used, the processing advances tostep S14.

In step S14, the I2C/I3C slave 46 receives a fixed communication settingnecessary for communication in the extension mode (for example, a copyfor each lane of PH/PF at the time of OLD, and so forth) and writes thecommunication. setting into the register 47 through the CCI slave 59.

In step S15, the 120/13C slave 46 receives a transmission. startingcommand of image data transmitted from the application processor 22 (instep S57 of FIG. 13 described later). Further, the 12C/I3C slave 46receives a communication. setting in compliance with the CSI-2 standardtransmitted together with the transmission starting command and writesthe communication setting into the register 47 through the CCI slave 59.

In step S16, the controller 60 decides whether or not transmission of apacket is to be started, and waits the processing until it is decidedthat transmission of a packet is to be started.

Then, in the case where it is decided in step S16 that transmission of apacket is to be started, the processing advances to step S17, and thecontroller 60 decides whether or not the data is to be transmitted inthe extension mode. Here, according to the content of the data of atransmission target, in the case where the data is such data as istransmitted, for example, in a use case of an example of applicationdescribed later, the controller 60 decides that the data is data to betransmitted in the extension mode.

In the case where the controller 60 decides in step S17 that the data isdata to be transmitted in the extension mode, the processing advances tostep S18, and an extension mode transmission process (refer to FIG. 12)of transmitting an extended packet ready for the extension. mode isperformed.

On the other hand, in the case where the controller 60 decides in stepS17 that the data is not data to be transmitted is the extension mode,the processing advances to step S19.

In step S19, the controller 60 decides whether or not a short packet isto be transmitted. For example, at the time of start of a frame and atthe time of end of the frame, the controller 60 decides that a shortpacket is to be transmitted.

In the case where the controller 60 decides in step S19 that a shortpacket is to be transmitted, the processing advances to step S20. Instep S20, the packet header generation. section 52 generates a packetheader and transmits a short packet having the conventional packetstructure to the application processor 22.

On the other hand, in the case where the controller 60 decides in stepS19 that a short packet is not to be transmitted (that is, a long packetis to be transmitted), the processing advances to step S21. In step S21,the packing section 51 places the image data into the payload, and theCRC calculation section 57 obtains a CRC to generate a long packethaving the conventional packet structure and transmits the long packetto the application processor 22.

After the processing in step S18, step S20, or step S21, the processingadvances to step 322, and the controller 60 ends the packet transmissionprocess. Thereafter, the processing returns to step S16, and then, theprocessing for transmitting a packet is similarly performed repeatedlytargeting a next packet.

FIG. 12 is a flow chart illustrating an extension. mode transmissionprocess performed by the process in step 318 of FIG. 11.

In step S31, the packet header generation section 52 generates a packetheader in which a VC, a data type, a WC, and so forth are placed, andtransmits the packet header to the application processor 22. At thistime, the packet header generation section 52 writes extension modesetting information indicating that the extension mode is used(DataType[5:3]=3b111) and extension type setting information foridentifying that the mode setting of the extension mode is the extensionmode 0 (DataType[1:0]=2b00), into the data type of the packet header.

In step S32, the application processor 22 decides whether or not anextended short packet is to be transmitted. For example, at the time ofstart of a frame and at the time of end of the frame, the controller 60decides that an extended short packet is to be transmitted.

In the case where the application. processor 22 decides in step S32 thatan extended short packet is to be transmitted, the processing advancesto step S33.

In step S33, the payload header generation section 53 transmits anextended payload header in which it is set at the first byte of thepayload that the data type (DataType[7:0]) is the short packet. At thistime, the payload header generation section 53 performs various settingsto be placed into the extended payload header (for example, OePH[7:0],OePF[3:0], or the like).

In step S34, the payload header generation section 53 places a framenumber (FN: FrameNumber) into the second byte of the payload andtransmits the same.

In step S35, the payload header generation section 53 generates andtransmits such an optional extended payload header as depicted in FIG.4, according to the setting (0ePH[7:0]) performed. in step S33.

In step S36, the CRC calculation section 57 obtains a CRC and transmitsthe CRC as the packet footer.

On the other hand, in the case where the application. processor 22decides in step S32 that an extended short packet is not to betransmitted (that is, a long packet is to be transmitted), theprocessing advances to step S37.

In step S37, the payload header generation section 53 transmits theextended payload header in which the data type (DataType[7:0]) is set toa packet other than the short packet at the first byte of the payload.At this time, the payload header generation section 53 performs varioussettings to be placed into the extended payload header (for example,OePH[7:0], OePF[3:0], or the like).

In step S38, the payload header generation section 53 generates andtransmits such as optional extended payload header as depicted. in FIG.5, according to the setting (0ePH[7:0]) performed in step S37.

In step S39, the packing section 51 packs image data supplied from theimage processing section 43 to generate a legacy payload and transmitsthe legacy payload.

In step S40, the payload footer generation section 54 generates andtransmits such an optional extended payload footer as depicted in FIG.4, according to the setting (OePF[3:0]) performed in step S37.

In step S41, the CRC calculation section 57 obtains a CRC and transmitsthe CRC as a packet footer.

Then, after the processing in step S36 or 541, the extension. modetransmission process is ended.

The image sensor 21 can generate and transmit an extended short packetor an extended long packet in such a manner as described above.

FIG. 13 is a flow chart illustrating a process in which the applicationprocessor 22 receives a packet.

For example, if the image sensor 21 is connected to the applicationprocessor 22 through the bus 23, then processing is started. In. stepS51, the controller 74 writes initial settings of the image sensor 21(for example, whether the C-PHY or the D-PHY is to be used as thephysical layer, and so forth) into the register 73 and transmits them tothe image sensor 21 through the CCI master 88 by using the I2C/I3Cmaster 72. Consequently, the initial settings are written into theregister 47 of the image sensor 21.

In step S52, the controller 74 recognizes whether or not the imagesensor 21 is compatible with the extension mode. For example, throughacquiring a set value (for example, extended PH/PF compatiblecapability) stored in the register 47 of the image sensor 21 by usingthe I2C/I3C master 72, the controller 74 can recognize whether or notthe image sensor 21 is compatible with the extension mode.Alternatively, the controller 74 can recognize in advance whether or notthe image sensor 21 is compatible with the extension mode, for example,on the basis of an input by a manual operation or the like.

In step S53, the controller 74 decides whether or not the image sensor21 is compatible with the extension mode and use of the extension modeis demanded by an application to be executed by the applicationprocessor 22.

In the case where the controller 74 decides in step S53 that the imagesensor 21 is not compatible with the extension mode or that use of theextension mode is not demanded, the processing advances to step S54.

In step S54, the controller 74 transmits a transmission starting commandof image data to the image sensor 21 by using the I2C/I3C master 72, Atthis time, the controller 74 also transmits communication. settings incompliance with the CSI-2 standard.

In step S55, the application processor 22 performs a conventional packetreception process of receiving a packet having the packet structureaccording to the existing CSI-2 standard, on the basis of thecommunication settings transmitted in step S54.

On the other hand, in the case where the controller 74 decides in stepS53 that the image sensor 21 is compatible with the extension mode andthat use of the extension mode is demanded by the application to beexecuted by the application processor 22, the processing advances tostep S56.

In step S56, the I2C/I3C, master 72 transmits fixed communicationsettings necessary for communication in the extension mode beforecommunication in the extension mode is started. Consequently, the fixedcommunication settings are written into the register 47 of the imagesensor 21 (step S14 of FIG. 11).

In step S57, the controller 74 transmits a transmission starting commandof image data to the image sensor 21 by using the I2C/I3C master 72. Atthis time, the controller 74 also causes the communication settings incompliance with the CSI-2 standard to be transmitted.

In step S58, the packet header detection section 81 confirms datasupplied from the physical layer processing section 71 to decide whetheror not reception of a packet is started, and waits its processing untilit is decided that reception of a packet is started. For example, in thecase where the packet header detection section 81 detects a packetheader from data supplied from the physical layer processing section 71,the packet header detection section 81 decides that reception of apacket is started.

In the case where the packet header detection section 51 decides in stepS58 that reception of a packet is started, the processing advances tostep S59.

In step S59, the packet header detection section 81 confirms the data.type of the packet header detected in step S58 and decides whether ornot the packet whose reception is started is an extended packetcompatible with the extension mode. For example, regarding the data typeof the packet header, in the case where the extension mode settinginformation indicates the extension mode (DataType[5:3]=3′b111), thepacket header detection section 81 decides that the packet whosereception is started is an extended packet.

In the case where the packet header detection section 81 decides in stepS59 that the packet whose reception is started is an extended packet,the processing advances to step S60, and an extension mode receptionprocess of receiving an extended. packet (refer to FIG. 14) isperformed.

On the other hand, in the case where the packet header detection section81 decides in step S59 that the packet whose reception is started is notan extended packet, the processing advances to step S61.

In step S61, the packet header detection section 81 confirms the datatype (DataType [5:0]) of the packet header detected in step S58 anddecides whether or not the packet whose reception is started is a shortpacket.

In the case where the packet header detection section 51 decides in stepS61 that the packet whose reception is started is a short packet, theprocessing advances to step S62. In step S62, the packet headerdetection section 81 receives a short packet having the conventionalpacket structure transmitted from the image sensor 21.

On the other hand, in the case where the packet header detection section$1 decides in step S61 that the packet whose reception is started is nota short packet (that is, reception of a long packet is started), theprocessing advances to step S63. In step S63, the unpacking section 87receives the payload of a long packet having the conventional packetstructure transmitted from the image sensor 21 and extracts image data,and the CRC calculation section 86 receives, as a CRC, the (WC+1)th bytetransmitted following the packet header.

After the processing in step S60, step S62, or step S63, the processingadvances to step S64, and the controller 74 ends the packet receptionprocess. Thereafter, the processing returns to step S58, and thereafter,a process of receiving a packet is similarly performed repeatedlytargeting a next packet.

FIG. 14 is a flow chart illustrating the extension mode reception.process performed by the process in step S60 of FIG. 13.

In step S71, the packet header detection section 81 decides whether ornot the mode setting of the extension mode is the extension mode 0. Forexample, regarding the data type of the packet header, in the case wherethe extension type setting information indicates the extension mode 0(DataType[1:0]=2′b00), the packet header detection section 81 decidesthat the mode setting of the extension mode is the extension mode 0.

In the case where the packet header detection section 81 decides in stepS71 that the mode setting of the extension mode s the extension mode 0,the processing advances to step S72. In step S72, the interpretation.section 83 receives the first byte of the payload as the extendedpayload header.

In step S73, the interpretation. section 83 confirms the data type(DataType[7:0]) of the extended. payload header received in step S72 anddecides whether or not The packet whose reception is started is anextended short packet.

In the case where the interpretation section 83 decides in step S73 thatthe packet whose reception is started is an extended short packet, theprocessing advances to step S74. In step S74, the interpretationsection. 83 receives an optional extended payload header according tothe setting (OePH[7:0]) placed in the extended payload header receivedin step S72.

In step S75, the CRC calculation. section 86 receives the (WC+1)th bytetransmitted following the optional extended payload header, as a CRC.

On the other hand, in the case where the interpretation section 83decides in step S73 that the packet whose reception is started is not anextended short packet (that is, reception of an extended long packet isstarted), the processing advances to step S76. In step S76, theinterpretation section 83 receives an optional extended payload headeraccording to the setting (OePH[7:0]) placed the extended payload headerreceived in step S72.

In step S77, the unpacking section 87 receives the legacy payload of theextended long packet transmitted from the image sensor 21 and extractsimage data.

In step S78, the interpretation section 83 receives an optional extendedpayload footer according to the setting (OePF[3:0]) placed in theextended payload footer received in step S72.

In step S79, the CRC calculation section 86 receives the (WC+1)th bytetransmitted following the optional extended payload. footer, as a CRC.

Then, in the case where it is decided in step S71 that the mode settingof the extension mode is not the extension mode 0, after the processingin step S75, or after the processing in step S79, the extension modereception process is ended.

The application processor 22 can receive an extended short packet or anextended long packet and acquire data in such a manner as describedhereinabove.

<Second Structure Example of Packet Structure>

A second structure example of the packet structure of a packet used incommunication between the extension mode compatible CSI-2 transmissioncircuit 31 and the extension mode compatible CSI-2 reception circuit 32is described with reference to FIGS. 15 to 16.

In the first structure example depicted in FIGS. 3 to 8 describedhereinabove, while emphasizing that the compatibility of the existingCSI-2 standard is maintained, the packet header and the packet footerare same as those of the packet structure of the existing CSI-2standard, and extension of the packet structure is achieved by theextended payload header, optional extended payload header, and optionalextended payload footer. In contrast, in the second structure exampledescribed below, the packet header and the packet footer are madedifferent from those of the existing CSI-2 standard, and extension ofthe packet structure is achieved by the extended packet header and theextended packet footer.

FIG. 15 depicts a packet structure of a short packet used in theextension mode of CSI-2 in the case where the physical layer is theD-PHY (such short packet is hereinafter referred to as the extendedshort packet for the D-PHY).

According to the extended short packet for the D-PHY depicted in FIG.15, the extension mode is identified from the data type placed in thepacket header same as that of the existing CSI-2 standard, similarly tothe case of the extended short packet for the D-PHY of the firststructure example depicted. in FIG. 4.

On the other hand, in the extended short packet for the D-PHY depictedin FIG. 15, a frame number is placed in the short packet data field of16 bits next to the data type of the packet header, similarly to thecase of the short packet in compliance with the existing CSI-2 standard.Then, following the packet header, an extended packet header configuredsimilarly to the extended payload header depicted in FIG. 4 istransmitted.

Accordingly, the application processor 22 that is the reception sideinterprets the data type placed in the extended. packet header and candecide, in the case where the data type is the extended short packet,that a frame number is placed in the data field of the packet header.

It is to be noted that the optional extended packet header of theextended short packet for the D-PHY depicted in FIG. 15 is configuredsimilarly to the optional extended payload header of the extended shortpacket for the D--PHY of the first structure example depicted in FIG. 4.However, since the optional extended packet header has a packetstructure in which the optional extended packet header is not embeddedin the payload, there is no necessity to add a CRC to the last.

FIG. 16 depicts a packet structure of a long packet used in theextension mode of CSI-2 in the case where the physical layer is theD-PHY (such long packet is hereinafter referred to as the extended longpacket for the D-PHY).

In the extended long packet for the D--PHY depicted. in FIG. 16,extended data is not embedded in the payload but is transmitted as partof the packet header or the packet footer. Accordingly, the WC of thepacket header at the top indicates the byte length of the payload,similarly to the existing standard.

FIG. 17 depicts a packet structure of a short packet used in theextension mode of CSI-2 in the case where the physical layer is theC-PHY (such short packet is hereinafter referred to as the extendedshort packet for The C-PHY).

Since the extended portion of the extended short packet for the C-PHYdepicted in FIG. 17 is transmitted as an extension of the packet headerin compliance with the existing CSI-2 standard, the extended portionsuch as the extended payload header is inserted after the frame number.Further, the packet header ends with a CRC similarly to the existingCSI-2 standard. The packet structure in which they are transmitted twicewith SYNC interposed therebetween is similar to that of the short packetin compliance with the existing CSI-2 standard.

FIG. 18 depicts a packet structure of a long packet used in theextension mode of CSI-2 in the case where the physical layer is theC-PHY (such long packet is hereinafter referred to as the extended longpacket for the C-PHY).

The extended long packet for the C-PHY depicted in FIG. 18 is differentfrom the extended long packet for the C-PHY of the first structureexample depicted in FIG. 8 in that the WC of the packet. header at thetop indicates a byte length of the payload, similarly to the existingstandard.

With such a packet structure of the extended packet of the secondstructure example depicted in FIGS. 15 to 16 as described above, theextended packet can cope with a more variety of uses than a conventionalart, similarly to the packet structure (FIGS. 3 to 8) of the extendedpacket of the first structure example.

However, the extended packet of the second structure example has thepacket structure in which extended data is not embedded in the existingpayload but the existing packet header or footer is extended. Therefore,in the case where the packet structure of the extended packet of thesecond structure example is adopted, as influence that, for example, maycause a change from a communication system used conventionally cannot beminimized in comparison with a case in which the packet structure of theextended packet of the first structure example is adopted. In otherwords, for example, a change for the existing SerDes transmissioncircuit 34 or SerDes reception circuit 35 (FIG. 2) is necessary.

As described above, by adopting the extended packet of the firststructure example, it is possible to cope with a variety of uses such asan in-vehicle use, and such an influence that a change of acommunication system used conventionally is necessary can be minimizedto construct as in-vehicle system.

Further, by adopting the extended packet of the second structureexample, although a change from a communication system usedconventionally is necessary, it is possible to cope with a variety ofuses such as an in-vehicle use.

<Modification of Image Sensor and Application Processor>

A modification of the image sensor and the application processor isdescribed with reference to FIG. 19.

The respective blocks forming the image sensor 21 of FIG. 9 and theapplication processor 22 of FIG. 10 described hereinabove are configuredso as to performm processing for both packets for the D-PHY and theC-PHY. In contrast, for example, blocks that perform processingexclusively for packets for the D-PHY and blocks that perform processingexclusively for packets for the C-PHY may both be provided such thatprocessing is switched between. them.

An image sensor 21A depicted in A of FIG. 19 includes a D layerprocessing block section 101, a C layer processing block section 102, aswitching section 103, and the controller 60.

The D layer processing block section 101 includes, among the blocksconfiguring the image sensor 21 of FIG. 9, those blocks that performprocessing exclusively for a packet for the D-PHY. The C layerprocessing block section 102 includes, among the blocks configuring theimage sensor 21 of FIG. 9, those blocks that perform processingexclusively for a packet for the C-PHY. The switching section 103performs switching under the control of the controller 60 such that apacket for the D-PHY generated by the D layer processing block section101 is output in the case where the D-PHY is used for the physical layerand such that a packet for the C-PHY generated by the C layer processingblock section 102 is output in the case where the C-PHY is used for thephysical layer.

An application. processor 22A depicted in B of FIG. 19 includes aswitching section 111, a D layer processing block section 112, a C layerprocessing block section 113, and the controller 74.

The switching section 111 performs switching under the control of thecontroller 74 such that a packet transmitted from the image sensor 21Ais supplied to either the D layer processing block section 112 or the Clayer processing block section 113. The D layer processing block section112 includes, among the blocks configuring the application processor 22of FIG. 10, those blocks that perform processing exclusively for apacket for the D-PHY. The C layer processing block section 113 includes,among the blocks configuring the application processor 22 of FIG. 10,those blocks that perform processing exclusively for a packet for theC-PHY.

In the image sensor 21A and the application processor 22 configured insuch a manner, before communication is started, a physical layer to beused can be set between. the controller 60 and the controller 74. Then,for example, in the case where the D-PHY is used for the physical layer,a packet for the D-PHY generated by the D layer processing block section101 is transmitted through the switching section 103 and suppliedthrough the switching section 111 to the D layer processing blocksection 112 to be processed. On the other hand, for example, in the casewhere the C-PHY is used for the physical layer, a packet for the C-PHYgenerated by the C layer processing block section 102 is transmittedthrough the switching section 103 and supplied through the switchingsection 111 to the C layer processing block section 113 to be processed.

<Example of Application of Extended Packet>.

It is examined to apply the extended packet described above, forexample, to such use cases as described below.

For example, it is examined to apply the extended packet to such a usecase that an image (RAW24) of a higher definition is transmitted.

For example, when image data is transmitted in the RAW form, RAW6, RAW7,PAW8, RAW10, RAW12, RAW14, RAW16, and RAN20 are defined as data types tobe placed. in the packet header in compliance with the existing CSI-2standard. In contrast, in recent years, in order to cope withself-driving using an in-vehicle camera, transmission of an image of ahigher definition is expected. Here, by applying the extended packet toincrease the number of bits of the data type, it is possible to define,for the data type of the extended payload header, RAW24 of a higherdefinition.

Further, it is examined to apply the extended packet to SmartROI that isa technology for transmitting only a noticed image region on a screenimage.

For example, nowadays, a large number of cameras are provided in astadium or an airport. In the case where entire images captured by thecameras are transmitted from the cameras to a cloud server through anetwork such as the Internet, it is supposed that shortage in bandwidthof the Internet or increase of the calculation amount or the data amounton the cloud side occurs. Therefore, it is expected. that, by cuttingout.

only a noticed image region and transmitting the noticed. image regionon the edge (camera side), bandwidth shortage of the Internet orincrease of the calculation amount or the data amount on the cloud. sideis suppressed.

In the case where such SROI is transmitted, in order to convey, to thereception side, which part in an entire image corresponds to the noticedimage region, it is necessary to transmit the coordinates of the upperleft corner of a rectangular region (ROI) together. Further, it isnecessary to send data regarding the entire captured screen image at apredetermined timing according to a command from the reception side.Accordingly, data regarding the SROI mage and data regarding the entireimage (existing packet header) in a unit or a frame exist in a mixedmanner, for example.

Thus, by applying the extended packet, it is possible to transmitcoordinate data, for example, of 16 bits or more regarding each of the Xcoordinate and the Y coordinate.

Further, a use case is investigated to apply the extended packet to GLDin which, even if channel deterioration. occurs, communication iscontinued by reducing the bandwidth or the number of lanes. It is to benoted that the GLD is a proposal examined in CSI-2 ver3.0.

For example, in self-driving, it is demanded that, even if part ofcables connecting the cameras is broken at the time of collision,communication be continued by using a cable that is not broken. suchthat the vehicle is stopped automatically after the vehicle takes refugeto the safety zone. Therefore, it is necessary for an in-vehicle camerainterface to include at least a disconnection detection function, andinformation such as a row number (16 bits) indicating which row theinformation is on the screen image, SourceID (8 bits) indicating whichcamera sends the information, a message counter (16 bits) indicative ofa transmission number, and so forth is required. Further, is the case ofuse is combination with such SROI as described above, it is conceivablethat such information is transmitted in a unit of a frame.

Therefore, such information can be transmitted by applying the extendedpacket.

<Example of Configuration of Computer>

While the series of processes (communication method) described above canbe executed by hardware, it can otherwise be executed by software. Inthe case where the series of processes is executed by software, aprogram that constructs the software is installed into a general-purposecomputer or the like.

FIG. 20 is a block diagram depicting an example of a hardwareconfiguration of a computer that executes the series of processesdescribed hereinabove according to a program.

In the computer, a CPU (Central Processing Unit) 201, a ROM (Read OnlyMemory) 202, a RAM (Random Access Memory) 203, and an EEPROM(Electronically Erasable and Programmable Read Only Memory) 204 areconnected to one another by a bus 205, Further, an input/outputinterface 206 is connected to the bus 205, and the input/outputinterface 206 is connected to the outside.

In the computer configured in such a manner as described above, the CPU201 loads a program stored, for example, in the ROM 202 and the EEPROM204, into the RAM 203 through the bus 205 and executes the program toperform the series of processes described above. Further, the program tobe executed by the computer (CPU 201) can not only be written in the ROM202 in advance but also be installed from the outside into the EEPROM204 through the input/output interface 206 or updated.

Here, in the present specification, processes performed according to aprogram by a computer does not necessarily be performed in a time seriesaccording to an order described as a flow chart. In particular, theprocesses performed according to the program by the computer alsoinclude processes executed in parallel or individually (for example,processes by a parallel process or by an object).

Further, the program may be processed by a single computer (processor)or may be processed in a distributed manner by a plurality of computers.Further, the program may he transferred to and executed by a remotecomputer.

Further, in the present specification, the term “system” is used tosignify an aggregation of a plurality of components (apparatuses,modules (parts), and so forth), and it does not matter whether or notall components are accommodated in the same housing. Accordingly,multiple apparatuses accommodated is separate housings and connected toeach other through a network are a system, and one apparatus in which aplurality of modules is accommodated in a single housing is also asystem.

Further, for example, the configuration described as one apparatus (orone processing section) may be divided. so as to configure a pluralityof apparatuses (or processing sections). Conversely, the configurationsdescribed as a plurality of apparatuses (or processing sections) in theforegoing description may be put together so as to configure a singleapparatus (or processing section). Further, needless to say, aconfiguration not described hereinabove may be added to theconfiguration of each apparatus (or each processing section). Further,if a configuration or operation of an entire system is substantiallysame, then some of the components of a certain apparatus (or processingsection) may be included in the configuration of another apparatus (oranother processing section).

Further, for example, the present technology can take a configurationfor cloud computing by which one function is shared and processedcooperatively by a plurality of apparatuses through. a network.

Further, for example, the program described above can be executed by anyapparatus. In this case, it is sufficient if the apparatus has necessaryfunctions (functional blocks and so forth) and can obtain necessaryinformation.

Further, for example, the respective steps of the flow charts describedhereinabove can be executed by a single apparatus or can be shared andexecuted by a plurality of apparatuses. Further, in the case where aplurality of processes is included in one step, the plurality ofprocesses included in the one step can be executed by one apparatus ormay be shared and executed by a plurality of apparatuses. In otherwords, it is also possible to execute a plurality of processes includedin one step as a process of a plurality of steps. Conversely, it is alsopossible to execute a process described as a plurality of stepscollectively as one step.

It is to be noted that, in a program to be executed by a computer,processes of steps that describe the program may be executed in a timeseries in the order as described in the present specification or may beexecuted in parallel or executed individually at necessary timings suchas when the process is called. In short, the processes in the respectivesteps may be executed in an order different from the order describedhereinabove unless they do not give rise to a contradiction. Further,the processes at the steps that describe this program may be executed inparallel to processes of another program or may be executed incombination with processes of another program.

It is to be noted that a plurality of present technologies described inthe present specification can be carried out alone and independently ofeach other unless they do not give rise to a contradiction. Needless tosay, it is also possible to carry out a plurality of desirable presenttechnologies together. For example, it is also possible to carry outpart or the entirety of the present technology described. in connectionwith any of the embodiments, in combination with part or the entirety ofthe present technology described in combination with another embodiment.It is also possible to carry out part or the entirety of the desirablepresent technology together with another technology, that is notdescribed hereinabove.

<Example of Combination of Configurations>

It is to be noted that the present technology can also take suchconfigurations as described below.

-   (1)

A communication. apparatus including:

a packet header generation. section configured to place settinginformation indicative of a condition set for data to be transmitted ina packet to generate a packet header in compliance with an existingCSI-2 standard; and

an extended header generation section configured to generate an extendedheader into which the setting information is to be placed separatelyfrom the packet header, in which

the packet header generation section places, into an unused regiondefined as a region that is not used in the existing CSI-2 standard withrespect to a data type that includes the setting information indicativeof a type of the data to be transmitted in the packet, extension modesetting information indicative of whether or not an extension mode usingthe extended header is used.

-   (2)

The communication apparatus according to (1) above, in which

the extended header generation section generates, as the extendedheader, an extended payload header that is arranged at a top of apayload in compliance with the existing CSI-2 standard.

-   (3)

The communication apparatus according to (1) above, in which

the extended header Generation section Generates an extended packetheader that is arranged following the packet header so as to extend astandard for the packet header, as the extended header.

-   (4)

The communication apparatus according to any one of (1) to (3) above, inwhich

the extended header generation section places optional extended headersetting information indicative of whether or not an optional extendedheader selectively transmitted according to a use is to be transmitted,into the extended header.

-   (5)

The communication apparatus according to any one of (1) to (4) above, inwhich,

in the case where the optional extended header is to he transmitted, theextended header generation section places, into the extended header, theoptional extended header setting information indicating that theoptional extended header is to be transmitted, and generates theoptional extended header following the extended header.

-   (6)

The communication apparatus according to any one of (1) to (5) above, inwhich

the packet header generation section places extension type settinginformation indicating which of a plurality of types of the extensionmode prepared as the extension mode is used, into the unused region.

-   (7)

The communication apparatus according to any one of (1) to (6) above,further including:

an optional extended footer generation. section configured to generate,in the case where the packet to be transmitted in the extension modeincludes an extended long packet in which data to be transmitted as apayload in the existing CSI-2 standard is placed, an optional extendedfooter that is arranged following a legacy payload into which the datais placed.

-   (8)

The communication apparatus according to any one of (1) to (7) above,further including:

a control section configured to control switching between transmissionof a packet having a packet structure in compliance with the existingCSI-2 standard and transmission of a packet having a packet structure inthe extension mode.

-   (9)

A communication. method by a communication apparatus that performscommunication, the communication method including:

placing setting information indicative of a condition set for data to betransmitted in a packet to generate a packet header in compliance withan existing CSI-2 standard; and

generating an extended header into which the setting information is tobe placed separately from the packet header, in which

extension mode setting information indicative of whether or not anextension mode using the extended header is used is placed into anunused region defined as a region that is not used in the existing CSI-2standard with respect to a data type that includes the settinginformation indicative of a type of the data to be transmitted in thepacket.

-   (10)

A program for causing a computer of a communication. apparatus thatperforms communication, to execute communication processing including:

placing setting information indicative of a condition set for data to betransmitted in a packet to generate a packet header in compliance withan existing CSI-2 standard; and

generating as extended header into which the setting information is tobe placed separately from the packet header, in which

extension mode setting information indicative of whether or not anextension mode using the extended header is used is placed into asunused region defined as a region that is not used in the existing CSI-2standard with respect to a data type that includes the settinginformation indicative of a type of the data to be transmitted is thepacket.

-   (11)

A communication apparatus including:

a packet header detection section configured to detect a packet headerin which setting information. indicative of a condition set for data tohe transmitted in a packet is placed, according to an existing CSI-2standard; and

an interpretation section configured to interpret the settinginformation placed is an extended header separate from the packetheader, in which

the packet header detection section causes switching to be performedbetween reception of a packet having a packet structure in compliancewith the existing CSI-2 standard and reception of a packet having apacket structure in an extension mode, according to extension modesetting information that is placed into an unused region defined as aregion not used in the existing CSI-2 standard with respect to a datatype including the setting information indicative of a type of the datato be transmitted in the packet and that indicates whether or not theextension mode using the extended header is used.

-   (12)

The communication apparatus according to (11) above, in which

the interpretation section receives, as the extended header, an extendedpayload header arranged at a top of a payload in compliance with theexisting CSI-2 standard and interprets the setting information placed inthe extended payload header.

-   (13)

The communication apparatus according to (11) above, in which

the interpretation section receives, as the extended header, an extendedpacket header arranged following the packet header so as to extend astandard for the packet header and interprets the setting information.placed in the extended header. (14)

The communication apparatus according to any one of (11) to (13) above,in which, in the case where optional extended header setting informationplaced in the extended header indicates that an optional extended headertransmitted selectively according to a use is transmitted, theinterpretation. section receives the optional extended header followingthe extended header and interprets the setting information placed in theoptional extended header. (15)

The communication apparatus according to any one of (11) to (14) above,in which

the packet header detection section recognizes which of a plurality oftypes of the extension mode prepared as the extension mode is used,according to extension mode type information placed in the unusedregion.

-   (16)

The communication apparatus according to any one of (11) to (15) above,in which,

in the case where the packet to be transmitted in the extension modeincludes an extended long packet in which data to be transmitted as apayload in the existing CSI-2 standard is placed, the interpretationsection receives an optional extended footer arranged following a legacypayload into which the data is placed, and interprets the optionalextended footer.

-   (17)

A communication method by a communication apparatus that performscommunication, the communication method including:

detecting a packet header in which setting information. indicative of acondition set for data to be transmitted in a packet is placed,according to an existing CSI-2 standard; and interpreting the settinginformation placed in an extended header separate from the packetheader, in which switching is performed between reception of a packethaving a packet structure in compliance with the existing CSI-2 standardand reception of a packet having a packet structure in an extensionmode, according to extension mode setting information that is placedinto an unused region defined as a region not used in the existing CSI-2standard with respect to a data type including the setting information.indicative of a type of the data to be transmitted in the packet andthat indicates whether or not the extension mode using the extendedheader is use.

-   (18)

A program for causing a computer of a communication apparatus thatperforms communication, to execute communication processing including:

detecting a packet header in which setting information indicative of acondition set for data to be transmitted in a packet is placed,according to an existing CSI-2 standard; and

interpreting the setting information placed in an extended headerseparate from the packet header, is which switching is performed betweenreception of a packet having a packet structure in compliance with theexisting CSI-2 standard and. reception of a packet having a packetstructure in an extension mode, according to extension mode settinginformation that is placed into an unused region defined as a region notused in the existing CSI-2 standard with respect to a data typeincluding the setting information indicative of a type of the data to betransmitted in the packet and that indicates whether or not theextension mode using the extended header is used.

It is to be noted that the present embodiment is not restricted to theembodiments described hereinabove and that various alterations arepossible without departing the subject matter of the present disclosure.Further, the advantageous effects described in the present specificationare exemplary and are not restrictive, and other advantageous effectsmay be given.

REFERENCE SIGNS LIST

11 Communication system, 21 Image sensor, 22 Application processor, 23and 24 Bus, 25 Serializer, 26 Deserializer, 27 Bus, 31 Extension modecompatible CSI-2 transmission circuit, 32 Extension mode compatibleCSI-2 reception circuit, 33 CSI-2 reception circuit, 34 SerDestransmission circuit, 35 SerDes reception circuit, 36 CSI-2 transmissioncircuit, 41 Pixel, 42 AD converter, 43 image processing section, 44Pixel CRC calculation section, 45 Physical layer processing section, 46I2C/I3C slave, 47 Register, 51 Packing section, 52 Packet headergeneration section, 53 Payload. header generation section, 54 Payloadfooter generation. section, 55 and 56 Selection section, 57 CRCcalculation section, 58 Lane distribution section, 59 CCI slave, 60Controller, 71 Physical layer processing section, 72 I2C/I3C master, 73Register, 74 Controller, 81 Packet header detection section, 82 Lanemerging section, 83 Interpretation section, 84 and 85 Selection section,86 CRC calculation section, 87 Unpacking section, 88 CCI. master

1. A communication apparatus comprising: a packet header generationsection configured to place setting information indicative of acondition set for data to be transmitted in a packet to generate apacket header in compliance with an existing CSI-2 standard; and anextended header generation section configured to generate an extendedheader into which the setting information is to be placed separatelyfrom the packet header, wherein the packet header generation sectionplaces, into an unused region defined as a region that is not used inthe existing CSI-2 standard with respect to a data type that includesthe setting information indicative of a type of the data to betransmitted in the packet, extension mode setting information indicativeof whether or not an extension mode using the extended header is used.2. The communication apparatus according to claim 1, wherein theextended header generation section generates, as the extended header, anextended payload header that is arranged at a top of a payload incompliance with the existing CSI-2 standard.
 3. The communicationapparatus according to claim 1, further comprising: a physical layerprocessing section capable of switching and executing both of physicallayer processes for C-PHY and D-PHY.
 4. The communication apparatusaccording to claim 1, wherein the extended header generation sectionplaces optional extended header setting information indicative ofwhether or not an optional extended header selectively transmittedaccording to a use is to be transmitted, into the extended header. 5.The communication apparatus according to claim 4, wherein, in a casewhere the optional extended header is to be transmitted, the extendedheader generation section places, as the optional extended headersetting information indicating that the optional extended header is tobe transmitted, an OePH selection flag, an MC (Message Count), and anRSID (in-vehicle line number and SourcelD) into the extended header andgenerates the optional extended header following the extended header. 6.The communication apparatus according to claim 1, wherein the packetheader generation section places extension type setting informationindicating which of a plurality of types of the extension mode preparedas the extension mode is used, into the unused region.
 7. Thecommunication apparatus according to claim 1, further comprising: anoptional extended footer generation section configured to generate, in acase where the packet to be transmitted in the extension mode includesan extended long packet in which data to be transmitted as a payload inthe existing CSI-2 standard is placed, an optional extended footer thatis arranged following a legacy payload into which the data is placed,wherein a (WC (Word Count) +1)th byte is transmitted following theoptional extended footer, as a CRC (Cyclic Redundancy Check).
 8. Thecommunication apparatus according to claim 1, further comprising: acontrol section configured to control switching between transmission ofa packet having a packet structure in compliance with the existing CSI-2standard and transmission of a packet having a packet structure in theextension mode, according to data content of a transmission target.
 9. Acommunication method by a communication apparatus that performscommunication, the communication method comprising: placing settinginformation indicative of a condition set for data to be transmitted ina packet to generate a packet header in compliance with an existingCSI-2 standard; and generating an extended header into which the settinginformation is to be placed separately from the packet header, whereinextension mode setting information indicative of whether or not anextension mode using the extended header is used is placed into anunused region defined as a region that is not used in the existing CSI-2standard with respect to a data type that includes the settinginformation indicative of a type of the data to be transmitted in thepacket.
 10. A program for causing a computer of a communicationapparatus that performs communication, to execute communicationprocessing comprising: placing setting information indicative of acondition set for data to be transmitted in a packet to generate apacket header in compliance with an existing CSI-2 standard; andgenerating an extended header into which the setting information is tobe placed separately from the packet header, wherein extension modesetting information indicative of whether or not an extension mode usingthe extended header is used is placed into an unused region defined as aregion that is not used in the existing CSI-2 standard with respect to adata type that includes the setting information indicative of a type ofthe data to be transmitted in the packet.
 11. A communication apparatuscomprising: a packet header detection section configured to detect apacket header in which setting information indicative of a condition setfor data to be transmitted in a packet is placed, according to anexisting CSI-2 standard; and an interpretation section configured tointerpret the setting information placed in an extended header separatefrom the packet header, wherein the packet header detection sectioncauses switching to be performed between reception of a packet having apacket structure in compliance with the existing CSI-2 standard andreception of a packet having a packet structure in an extension mode,according to extension mode setting information that is placed into anunused region defined as a region not used in the existing CSI-2standard with respect to a data type including the setting informationindicative of a type of the data to be transmitted in the packet andthat indicates whether or not the extension mode using the extendedheader is used.
 12. The communication apparatus according to claim 11,wherein the interpretation section receives, as the extended header, anextended payload header arranged at a top of a payload in compliancewith the existing CSI-2 standard and interprets the setting informationplaced in the extended payload header.
 13. The communication apparatusaccording to claim 11, further comprising: a physical layer processingsection capable of switching and executing both of physical layerprocesses for C-PHY and D-PHY.
 14. The communication apparatus accordingto claim 11, wherein, in a case where optional extended header settinginformation placed in the extended header indicates that an optionalextended header transmitted selectively according to a use istransmitted, the interpretation section receives the optional extendedheader following the extended header and interprets, as the settinginformation placed in the optional extended header, an OePH selectionflag, an MC (Message Count), and an RSID (in-vehicle line number andSourceID).
 15. The communication apparatus according to claim 11,wherein the packet header detection section recognizes which of aplurality of types of the extension mode prepared as the extension modeis used, according to extension mode type information placed in theunused region.
 16. The communication apparatus according to claim 11,wherein, in a case where the packet to be transmitted in the extensionmode includes an extended long packet in which data to be transmitted asa payload in the existing CSI-2 standard is placed, the interpretationsection receives an optional extended footer arranged following a legacypayload into which the data is placed, and interprets the optionalextended footer, and a (WC (Word Count) +1)th byte is received followingthe optional extended footer, as a CRC (Cyclic Redundancy Check).
 17. Acommunication method by a communication apparatus that performscommunication, the communication method comprising: detecting a packetheader in which setting information indicative of a condition set fordata to be transmitted in a packet is placed, according to an existingCSI-2 standard; and interpreting the setting information placed in anextended header separate from the packet header, wherein switching isperformed between reception of a packet having a packet structure incompliance with the existing CSI-2 standard and reception of a packethaving a packet structure in an extension mode, according to extensionmode setting information that is placed into an unused region defined asa region not used in the existing CSI-2 standard with respect to a datatype including the setting information indicative of a type of the datato be transmitted in the packet and that indicates whether or not theextension mode using the extended header is used.
 18. A program forcausing a computer of a communication apparatus that performscommunication, to execute communication processing comprising: detectinga packet header in which setting information indicative of a conditionset for data to be transmitted in a packet is placed, according to anexisting CSI-2 standard; and interpreting the setting information placedin an extended header separate from the packet header, wherein switchingis performed between reception of a packet having a packet structure incompliance with the existing CSI-2 standard and reception of a packethaving a packet structure in an extension mode, according to extensionmode setting information that is placed into an unused region defined asa region not used in the existing CSI-2 standard with respect to a datatype including the setting information indicative of a type of the datato be transmitted in the packet and that indicates whether or not theextension mode using the extended header is used.